Conventionally, good quality water from sea/brackish water is being produced with known process of REVERSE OSMOSIS, MULTI STAGE FLASH EVAPORATION or with the conventional EVAPORATION & CONDENSATION method. All these above methods require huge quantity of energy by way of electricity and/or thermal energy to evaporate/separate water from brackish/sea water. The FGEPSC (FLARED, GAS EXHAUST, PNEUMATIC, SATURATION AND CONDENSATION) process and system envisages the effective utilization of the waste heat and water vapor, (present in the fossil fuel fired boiler flue gas and turbine exhaust gases that are being liberated into the atmosphere, and also heat available in flared hydrocarbon gases being dissipated into the atmosphere). Waste heat present in the flue/exhaust gases generated from heat sources other than that mentioned above can also be used for the production of high purity water in large quantity as stated above by desalination of brackish/sea water.